Focusing shutter



y 1929. R. M. HILL I 1,713,338

FOCUSING HUTTER Filed Feb. 8, 1927 FIE-.1 30

INVENTOR #065901. MAL

FIELZ 5),

Patented May 14, 1929.

PATENT OFFICE.

RGGER M. HILL, OF WASHINGTON, DISTRICT OF COLUMBIA.

FOCUSING Original application filed January 12, 1927, Serial No. 160,644. Divided and February 8, 1927. v

This invention relates to stereopticons,spotlights and other forms of projection appara tus, more especially it is directed to a device for focusing.

One object of this invention is to provide a combined shutter and douser, so interrelated in their action-as to initially completely'occult the entire light beam and then permit the projection of a beam of restricted dimensions.

Another object of this invention is to provide a combined shutter and douser, the douser overlying the shutter to normally close a miniature light aperture, but operable after closure of the shutter to expose the miniature light aperture.

IVith these and other objects in View this invention consists in certain novel details of construction, combination and arrangement of parts to be more particularly hereinafter set forth and claimed.

This invention is a division of the subject matter set forth in the companion application executed January 12, 1927, Ser. No. 160,644 for an auxiliary focusing device and projection apparatus.

Briefly stated this invention consists of a means controllable by a single operation, for instantaneously blocking the light source at the lamp house from the remainder of the apparatus, and for reducing the projection beam to a dimension which'permits of the focusing of a distinct image of the luminant at a predetermined point along the optical axis. v r

Referringmore particularly to the accompanying drawings in Which corresponding parts are indicated by similar reference characters:

1 is a side elevation partly in section showing a lamp house and projectorinoperafive position. I

, Fig. 2 is a front elevation of the shutter, dousen' cam stop, crank handle and lamp house shield, showing the shutter and douser in open position; and I Fig. 3 is a rear elevation of the shutter, louser and crank handleshowing the shutter in closed position and the douser in either open or closed positions. v

In describing the details of construction SHUTTER.

this application filed Serial No. 166,804.

I all but a portion of the projection beam which is allowed to pass through a pin hole in a shield and is projected on an intercepting diminutive screen which generally consists of card held by the operator.

This method is not only found incon venientbut also inaccurate since the image which is produced by pin hole projection is very indistinct and as compared to one that is formed by a projection opening of material size and at a definite distance from said 7 opening.

Referring to Fig. 1 numeral (1) designat-es the lamp house and (2) the projector. In connection with. the lamp house is shown the incandescent lamp (3), reflector 1), condenser lenses (5) and (6), lens casing (7), lens casing supporting rods (8) and (9), supporting frame (10), slide frame (11), light shield (12), douser (13), shutter (14) and crank (15);

The lamp house (1) is connected to the projector (2) by means of the link (16). In con nection With the projector is shown the projector housing (17) and frame door (18). Attached to the frame door (18) and projecting perpendicularly therefrom is the supporting rod (19), constituting a bracket to Which is adjustably attached the auxiliary condenser frame (20), auxiliary condenser shield (21) and target (22) Which are fully described in the aforementioned copending application. I

The lamp house shutter and douser, which constitutes the patentable features of this invention, willnow be described. The shutter (14) which is placed directly in front of the condenser lenses (5) and (6) consists in a half circular half rectangular shield, which is drilled centrally and at one corner of its 109 which acts as a stop.

5 is rotatably mounted. in a bearing (25) formed in the slide frame (-11).

The centrally drilled opening (26) in the shutter (14:) is for the projection of a central pencil ray which will be hereinafter further described. The undrilled corner of the rectangular portion of the shutter is cut off to form an abutting edge ('28) which, when the shutter is lowered comes into contact with the upper portion of the supporting frame Atone extremity of'the s' l1aftl(2i) is rigid- 1y attached a douser 13) consisting of a corn- I paratively narrow metallic strip having slightly diyerging opposite edges and which islimited in iitsrelative angular movement with respect to the shutter (14) .by a narrow strip formed between two parallel slits cut in the shutter. The strip is raised suf iiciently beyond the surface of the shutter to perm; the insertion of the douser thereunder, "and sufficient clearance is allowed ateither end ofjthe raised strip 29;) to permit a slight movemento f the douser relative'to the shutter, as shown by dotted lines in 3. This slight movement is required to uncover the central opening after the shutter is closed as will hereinafter be described.

At one end er the crank is attached a thumb wheel (30) and at the opposite end is 7 formed a boss which is drilled to fit the shaft (24) to which it is rigidly attached. On the external-surface of this boss is cut a cam ;(31) which reacts against the plunger (.32) slidably mounted'in the circularly drilled openthe lug (34) projectingfrom the upper portion of the slide frame (11). One end he plunger (32) is rounded, the other flat, the flattened end serving as a bearing surface for contact with 'a coil spring (35) which is heid within the circular opening (33) by means oi the mach ne screw On the surface of the cam 1s cut a groove i into whiclithe rounded end ,of

the plunger moves when the cam is reso tated nntiithegrooye (37') registers with the circularly drilled opening (33), thus retaining the douser (13) and shutter in an elevated'positionas shown in F g. 2.

The flattened surface (8) of the c ain. (31) r, is cut so that the distance from the axis of the to points on its surface increase directly as the distance increases from (the groove (37.). Thus t w ll b e seen that in lowering the douser the cam reacts against the action f t ge 2) n since the hutter (14 is rotatablyi mounted on the shaft it" simply follows the douser until'it reaches its lowermost position here the shutter is t pped y ab tt the HPPQ frame (10); If the cam is then rotated farther the ther, but on further movementof thecrank i (15) the douser which is held in its upright position by the coaction between the cam and the plunger (-32) will be rotated until the control opening in the shutter is uncovered. From the above description it is seen that the shutter and douser are operated by a single control means which shuts off the light at the lamphouse from the rest of the appa- .ratusanduncovers the opening 26) to per mit the emergence of a restricted beam for auxiliary projection purposes as explained in my aforementioned c'opending application.

Although in thecforegoing certain elements have been described as bestadapted to perform the functions allotted them, nevertheless it is to be understood that various minor changes may be resorted to within the scope of the appended claims without departing from or sacrificing any ,of the principles of he inren ipl li i I Having described my invention; 'what I claim as new and wish to secure by Letters Patent is z v V r 1. In a projection apparatus the combination with a radiant condenser and objective system, optically associated to produce a beam snitable for projection purposes of a shuttei operable into and out of the path of the beam and having a central opening therein, a ,d ouser normally closing said opening, said denser being rotatably mounted adjacent to and concentric with said shutter and adaptedto momentarily expose said opening to produce a beam of restricted dimensions. I '2. In a projection apparatus the combina tion witha radiant condenser and objective system, optically associated to produce a beam snitable for projection purposes; of a shutter mountedin front of the condenser systenn rotatable into and'out of the path of the beamand having a central opening there. in, a 'douser normally closing the shutter opening, said douser being rotatably mounted Ill) adjacent to and concentric with said shutter andadapted to momentarily expose said openlng to produce a beam of restricted dimensions.

'3. In a projection apparatus the combina tion with a radiant condenser andfobjective system, optically associated to produce a beam suitable for projection purposes of a shutter adapted to intercept the beam in shutter having a central opening, revolvably mounted upon a rotatable shaft, a douser rigidly mounted on said shaft and adapted to normally close the shutter opening, and operable to expose said opening to produce a beam of restricted dimensions.

5. In a projection apparatus the combination with a radiant condenser and objective system, optically associated to produce a beam suitable for projection purposes; of a shutter having a central opening revolvably mounted upon a rotatable manually controlled shaft, a douser rigidly mounted on said shaft and adapted to normally close the shutter opening, and operable to expose said opening to produce a beam of restricted dimensions.

6. In a projection apparatus the combination with a radiant condenser and objective system, optically associated to produce a beam suitable for projection purposes; of a shutter having a central opening revolvably mounted upon a rotatable manually controlled shaft, means to govern the degree of rotation of said shaft, and a douser rigidly mounted thereon and adapted to normally close the shutter opening and operable to expose said opening to produce a beam of restricted dimensions.

7. An assembly for projection apparatus comprising in combination a shutter rotatable through a predetermined angle, a douser simultaneously operable with the shutter and normally closing a central opening therein, said douser being mounted for differential movement with respect to the shutter when the latter has attained the limit of its angular movement and means in connection with the douser to effectits restoration to normal position.

8. An assembly for projection apparatus comprising in combination a shutter, a douser overlying the shutter and normally closing a centrally arranged opening therein, said shutter and douser being concentrically mounted and simultaneously operable through a predetermined angle, means afiording a differential movement between shutter and douser when the former has attainedthe limit of its angular movement and additional means in connection with the douser to effect its restoration to normal position.

9. An assembly for projection apparatus comprising in combination a supporting structure formed with an opening-for the passage of a projection beam, a rotatable shutter having open and closed positions relative to said opening, a douser operable with the shutter and normally closing a centrally arranged opening therein, means in connection with the douser to effect its yieldable retention in normal position, and interacting means between shutter and douser permitting a limited movement of the latter after the former has attained its closed position.

10. An assembly for projection apparatus comprising in combination a supporting structure formed with an opening for the passage of aprojection beam, a shutter rotatable into open and closed positions with respect to said openings, a douser operable with the shutter and normally overlying an opening centrally arranged in the shutter, spring pressed means in connection with the douser to yieldably effect its retention in normal position and interacting means between the shutter and douser permitting a limited movement of the latter afterthe former has attained its closed position.

11. An assembly for projection apparatus comprising in combination a supporting structure formed with an opening for the passage of a projection beam, a rotatable shutter having open and closed positions with respect to said opening, a douser operable with the shutter and normally overlying a centrally arranged opening in the shutter, means in connection with the douser to effect its yieldable retention in normal position and a strap connection between shutter and douser, the length of said connection being such as to permit a limited movement of the douser after the shutter has attained its closed position.

12. An assembly for projection apparatus comprising in combination a supporting structure formed with an opening for the passage of a projection beam, a shutter rotatable into open and closed positions with respect to said opening, a douser simultaneously operable with the shutter and normally closing a centrally arranged opening therein, a strap carried by the shutter and embracing the douser, the length of the strap being such as to permit a limited movement of the douser when the shutter has attained a closed position, and means in connection with the douser to effect its yieldable retention in normal position, said means including a'rotatable shaft associated with the shutter and douser, cam surfaces formed on the shaft and a spring pressed plunger coacting with such surfaces.

13. An assembly for projection apparatus comprising in combination a supporting structure formed with an opening for the passage of a projection beam, a shaft rotatably mounted upon said structure, a shutter loosely carried by the shaft and adapted to be disposed in open and closed positions with re-V and shutter, and ineansyiel'dably maintaining speet to szud opening, a douser keyed to vstud the douser in its normal'positien, sald means 1 shaft andnormaliy located 1n overlying relainclud ng cam surfaces on said shaft, the

I tion with respect to anppening centrally a-rlocation of said surfaces corresponding to ranged in the shutteiyav strap carried by the open and closed positions of the shutter and shutter and embracing the dousei" the length a spring pressedplunger eoacting With said limited relative movement between douser of said strap being such asto permit of a surfaces. 7 r V M HILL. 7 

